Wire line hydraulic pulling tool



Apnl 8, 1958 D. M. STEWART WIRE LINE: HYDRAULIC PULLING TooL.

Filed July 21, 1954 mii v IY United States Patent O il al.

WIRE LINE HYDRAULIC PULLING TOOL Douglass M. Stewart, Houston, Tex., assigner, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, N. J., a corporation of Delaware Application July 21, 1954, Serial No. 444,798

6 Claims. (Cl. 1156-98) This application is directed to a pulling tool adapted to be lowered into a string of pipe on a wire line and to be actuated by the wire line to exert a pull on a stuck body or object in said pipe.

Other objects and advantages of the present invention will be seen from the following description taken in conjunction with the drawing in which Fig. 1 is an elevation, partly in section, showing the upper end of an embodiment of the present invention;

Fig. l-A is a View, partly in section, showing the lower end of the embodiment, Figs. 1 and l-A taken together showing the complete assembly;

Fig. 2 is a view taken along line 2 2 of Fig. 1;

Fig. 3 is an elevational view of an element removed from the device of Fig. l;

Fig. 4 is a sectional view taken along the line 4 4 of Fig. l;

Fig. 5 is a fragmentary showing of the slip elements of Fig. l in gripping engagement with the casing wall;

Fig. 6 is a fragmentary View illustrating the release of the overshot of Fig. 1;

Fig. 7 illustrates another overshot engaged with the tapered slip setting element; and

Fig. 8 is a fragmentary view showing a device correspending to that of Fig. l-A but provided with a plurality of power cylinders with a power piston in each cylinder.

Turning now specifically to the drawing, a section of pipe A which may, for example, be a string of casing in a borehole which has a stuck body or object B therein. lt is desirable to exert a greater force on body B to release it than can be secured by engaging it with a con veutional fishing tool or overshot carried on the end of a wire line and then exerting an upward pull on the wire line.

A wire line hydraulic pulling tool which allows a substantially greater force to be exerted on an object stuck in a section of pipe than can be exerted merely by the rse of a wire line is shown arranged within casing A in Figs. 1 and l-A which taken together show the complete embodiment.

The wire line hydraulic pulling tool has an elongated :asing C which forms a pump or power cylinder D and a ower motor cylinder E.

Threadedly connected into the upper end of casing C s a bushing member 8. Threadedly connected into the ipper end of bushing 8 is a tubular neck member H. lirranged about neck member H are a pluraliy of slip trms designated by the letter G. As can be seen in Figs. 1 and 2, the slip arms G terminate at their lower :nds in a common collar section G' which is `slidably lrranged on neck `member H. The slip arms G are of he leaf spring type and tend to retract inwardly toward leek member H. A tapered slip setting member J is also lidably mounted on neck member H with its tapered urface slidably engaging a corresponding tapered surace on the inside of slip arms G.

For convenience in considering the operation of the ICC device, the upper portion may be considered to be a slip setting section, the central portion a pump or power section and the lower portion a motor or pulling section. Pump cylinder D with pump plunger K connected to piston -rod L slidably arranged therein may be considered the power section of the tool. The motor section may `be considered to consist of piston rod O connected to piston M slidably arranged in cylinder E,

Slidably arranged within cylinder D is piston K connected to piston rod L. Slidably arranged within cylinder E is a piston M. Piston M is mounted on piston rod O the lower end of which extends through the bottom of cylinder E and is" provided with a pulling head assembly P. It is to be understood that the pulling head P is shown for illustrative purposes and that any suitable type of engaging means known to the art, such as an overshot, catch, or spear may be used.

The outlet end of the pump cylinder D the chamber above plunger K) is in liuid communication with the high pressure end of the motor cylinder E (the chamber below piston M) by means of port 29a, passage 29 and port 29h. The low pressure end of the motor cylinder E (the chamber above piston M) is in iluid communication with `the inlet end of the pump cylinder D (the chamber below plunger K) by means of passage 41 in partition 40 and passage 46a provided by fitting 46 which is connected into the lower wall end ot" the pump cylinder D. An elastic means for biasing pump plunger K toward the lower end of the pump cylinder D is provided by spring 2.3 which is arranged around the piston rod L with its upper end abutting the lower end of bushing 8 and its lower end abutting the top of pump plunger K.

Pump plunger K is provided with packing means 24 about its outer periphery for sealingly engaging the plunger with the wall of pump cylinder D. Fluid communication between the underside and the upper side of plunger K during the plungers downstroke is provided by passage 25a in seat member 25, spring biased ball valve 26 and passages 25h provided in plunger K above the ball valve 26. During the upstroke of plunger K, this fluid communication is closed oit by spring biased ball valve 26.

The upper end of piston rod L extends through bushing 8 in the upper end of pump cylinder D, tubular neck member H, tubular portion 13 of memberl, and terminates in a running head 11. As shown in Fig. 1, the assembly is suspended in casing A by means of a releasable spear assembly Q engaging running head 11. Assembly Q is connected to wire line 12. A iluid seal is maintained around piston rod L by packing means 8a in bushing 8. Tubular portion 13 of member I is provided with a retrieving head 14, the purpose of which will be described later. Neck member H extends into cylindrical chamber 16 of member and terminates in a head 17.

Member J and central passage lo therein define an inwardly extending shoulder 1li which engages with the lower surface of head i7 of neck H and thus limits the extreme movement between members I and H in one direction while the extreme movement in the other direction is limited by contact of the lower surface of tubular portion 13 with the upper surface of head 17. At the lower end of neck H is provided a slot 21 the upper end of which is bounded by shoulder 22. A block member 20 carrying shear pin i9 is fixed to the collar portion G of slip members or arms G and extends into the slot 21. Block 20 is secured to piston rod L by the shear pin 19. Upon upward pull on wire line 12 piston rod L, block 20 and slip member G move upwardly until block 2l) comes into contact with stop 22 whereupon if an additional force is exerted on piston rod L it causes shear aecomo.`

piu 19 to fail and allows free movement of piston rod L with regard to slip member G.

An assembly R is provided to equalize the pressure of the device with the pressure in the fluid in the well bore as the device is lowered from the surface of the eart down through the borehole into position. The assembly consists of a flexible walled chamber 44 which is connected through htting 45 into wall member di@ of motor cylinder E. The interior of chamber 44 is in fluid communication with the casing annulus surrounding cylinder E by means of passage 43 provided in wall member 4t).

When assembling the device at the surface a suitable hydraulic fluid such as oil, water or an emulsion is usually placed in cylinders D and E to lill completely these cylinders and connecting passages while llexible walled chamber 4d with its connecting passage 43 has air at atmospheric pressure. Then when the device is placed in the borehole the pressure within chamber ld reaches equilibrium with the tiuid in the well and the expansion or contraction in chamber '44 in turn equalizes the pressure in chamber E, with the pressure within the borehole. Thus, the pressure on the lower pressure side of motor cylinder E and on the inlet side of pump cylinder D is in equilibrium with the lluid in the well surrounding the device.

Motor piston M is provided with sealing means 9i) which make a tluid-tight seal with the wall of cylinder E and packing means 9i are provided for sealing piston rod O in a huid-tight manner where it passes through the lower or high pressure end of cylinder E.

Another embodiment of the motor section of the present invention is shown in 1Eig. 8 it being understood that the structure shown in Fig. 8 taken with that shown in Fig. l is a complete hydraulic tool. The embodiment of Fig. 8 differs from the structure shown in Fig. l-A in having a plurality of power cylinders with each cylinder provided wtih a piston. Thus, the power assembly consists `of a plurality of vertically aligned pistons mechanical ly associated with a piston rod which in turn has a free end extending below casing C and provided with a means P, such as in'Fig. l-A, at its lower end for engaging with the body to be pulled from a section of pipe.

ln the embodiment of Fig. 8, two power cylinders E and F are provided with power pistons N and M', respectively, slidably arranged therein. Each of these pistons is provided with sealing means 9d engaging with the walls of their respective cylinders. Cylinders E and F are divided into two chamber by means of a wall member 92 provided with packing means 91. The two pistons are interconnected by piston rod O with the piston -rod O extending below piston M and also extending through the bottom of power cylinder F. The chamber formed under each piston is iluidly connected to the outlet of pump cylinder D by means of uid pasageway 29', 29C and 2%'. The chamber immediately above each piston is iluidly communicated with the underside of plunger K by means of port 33, passageway 31 and port 32, all of which are included in piston rod O. The lower end of piston rod O extending through the bottom of power cylinder F, as in Fig. l-A, is also sealed oit by a packing ring 91. The portion of piston rod O extending through wall member 92 is tluidly sealed therein by sealing ring 91a. Thus, it will be obvious that in operation the device of Fig. 6 taken with Fig. l acts in identically the same way as does the embodiment shown by Figs. 1 and 'l-A with the exception that the structure shown in Fig. 6 has plurality of power cylinders and thus is able to exert a greater pull on the stuck object.

lt will be obvious that while a single piston motor is shown in .Fig l-A and a two-piston motor is shown in Fig. 6 that a three piston motor or any greater number motor cylinders and pistons may be provided as desired it a greater pull is to be developed. By-pass valves (not shown) are provided to facilitate lling cylinders D, E and F with lluid .and i'or cleaning.

. assembly is not sufficient to compress spring 23.

The use of the device for the purpose of exerting a pulling force on a body stuck in a pipe will now be described in conjunction with the embodiments in Figs. l and l-A. The device is assembled with the parts in position shown in Figs. 1 and l-A with hydraulic iluid in cylinders D and E and connecting passages and with fraugible pin 19 holding member Ztl and arms G to pump piston rod L. Referring to Figs. l and l-A it will be seen that as the device is lowered into the casing A, the spring 23 is of sufficient strength so as to bias plunger K to its lowermost position within pump cylinder D. As this also biases rod L down and since slip arms G are connected to rod L by shear pin 19, the arms G are also pulled down to their lowermost position and abut on top of bushing 8. ln other words, the entire w ight of the The tension in leaf spring slip arms G is also enough to keep slip setting wedge member I from sliding down on neck member H and pushing out the arms G toward. the pipe A. Head l1 of piston rod L has over-shot Q engaged therewith and the assembly is lowered on wire line 12 through the casing until assembly P engages with stuck object B. The operator at the surface then exerts a pull on suspending wire line 12. This pull is transmitted to piston rod L and causes it to move upwardly. Upward movement of piston rod L produces two simultaneous elects. The force exerted from piston rod L through pin 19 and block 20 causes slip arms G to be forced upwardly and since piston rod L slides upwardly with respect to slip setting assembly I the slip arms G are forced outwardly as well as upwardly. However, the movement of piston rod L upwardly carries with it plunger K which, in turn, forces hydraulic lluid from pump cylinder D through passage 2@ and side port 29a and into the high pressure end of motor` cylinder E. The power fluid exerts a thrust downward on casing C and upward against piston M but since piston M is attached through piston rod O to body B, it is kept from moving upwardly at this time since the stuck object will present a greater resistance to movement than casing C so that the force exerted on casing C causes it to move downwardly. However, since member H is attached to `casing C, the downward movement of casing C is transmitted through shoulder 13 to pullslip setting wedge l downwardly into slip arms G which are at this time moving upwardly, as noted supra, this forces teeth 59 to firmly engage with the walls of pipe A. After the slips are set a continued pull on wire line 12 causes continued upward movement of piston rod L and brings shear pin housing tl into contact with shoulder 22 of neck H which in turn causes shear pin 19 to fail and so releases piston rod L for free reciprocating movement with respect to slips G.

After the slip arms G yare set in pipe A, piston rod L is moved upwardly by continuing the pull on wire line 12 so as to cause pump plunger K to force hydraulic iluid from pump cylinder D through passage 29 into the high pressure end of motor cylinder E. This force in turn is transmitted through piston rod O and gripping assembly P to stuck body B. If body B begins to move, motor piston M will be moved upwardly in motor cylinder E and tiuid is exhausted from the low pressure side of motor cylinder E through pasages 41 and 46a to the inlet end of pump cylinder D. Thus, the piston rod L may draw pump plunger upwardly to the top of its stroke until it is stopped by the compressed spring 23. Thereupon if the operator releases wire line 12, spring 23 will force pump plunger K downwardly to the bottom of pump cylinder D and when plunger K reaches the bottom of its stroke the operator at the surface may give the wire line 12 another upward movement and force plunger K upwardly through another stroke. This operation may be repeated to give rapid strokes of pump plunger K until the stuck object B either is free or piston M with piston rod O has reached its uppermost position.

If, `while applying a`pulling force to the object B it were to become suddenly loosened,"causing the casing C to` jump up, the slip arms G Would not become disengaged from the casing A since the neck member H is free to slide within `the slip arms G and member I. At this point the tool may be released and removed from the hole by lirst dropping over-shot S, as shown in Fig. 6, down wireline 12 which causes the jaws of wire line spear to open` so that the wireline is free from the tool and may then be` retrieved. As the next step a larger over-shot, over-shot T as shown in Fig. 5, is run back into the hole on wire line 12. Over-shot T engages shoulder 14 of slip setting wedge l and when a strainis taken on a wire line, `the slip setting wedge J is pulled upwardly out of slip arms G, the slip arms then retract, retracting teeth 59 from the wall of the tubing so that the slip arms are free and with the object B still engaged with pulling head T may be withdrawn from the borehole.

In the eventthat the stuck object is drawn upwardly by pulling head P but does not become free so that it can be withdrawn from the borehole by the `time piston M with piston rod Oreaches the upper end of its stroke, the releasing socket 69 at the bottom of casing C engages with `jaws 70 of pulling head assembly P and releases assembly P from object B.

When this occurs the slip arms G still havetheir teeth 59engaged withpipe A. In order to release `the device, over-shot S, shown in Fig. 7, may be dropped down wire line 11 to releaseV over-shot Q and thereafter larger over-shot T adapted for engaging shoulder 14 of assembly L may be used to release slips G in the same manner as` indicated in Fig. 7 and the assembly removedfrom theborehole with the object B remaining in the casing.

VIn the case described in the preceding paragraph if another attempt is to be made' to retrieve body B, the parts of the assembly are returned to their original positions yas shown in Figs. l and l-A and the device then lowered in the borehole suspended from Wire line 12 by over-shot Q and the operation repeated.

It will be seen that in the embodiments of the invention shown and described in the present case that by means of hydraulic pressure the pulling force exerted through a wire line is multiplied and that by means of slips set against the Wall of the `tubing the pulling strain p is transmitted to the wall of the tubing. Thusit is possible to exert a continuous pull against a stuck object many times in excess of the tensile strength of the wire line which is used to transmit the power.

Having fully described and illustrated preferred embodiments of the presentinvention, what is desired to be claimed is:

l. In a hydraulic pulling tool, a housing comprising, a slip setting section, a pump section and a pulling section; said pump section comprising a pump cylinder having a pump plunger slidably mounted therein and dividing said pump cylinder into an inlet end and an outlet end; said pulling section comprising a motor cylinder having a power piston slidably mounted therein and dividing said motor cylinder into a high pressure end and a low pressure end; first passage means liuidly communicating said pump cylinder outlet end and said motor cylinder high pressure end, second passage means liuidly communicating said pump cylinder inlet end and said motor cylinder low pressure end, a rst piston rod connected to said pump plunger and having an upper end extending sealingly through the outlet end of said pump cylinder, biasing means arranged on said first piston rod to bias said plunger toward the inlet end of said pump cylinder; said slip setting section comprising a cylindrical neck connected to the upper end of said housing and having slidably mounted therein said first piston rod and having a longitudinally extending slot in its lower end and a head at its upper end, slip arms slidably mounted on said neck, a trangible pin member vertically mov- 6 able in said slot connecting said slip arms and said first piston rod, an annular member slidably mounted for limited vertical movement on said neck member and having an outer tapering surfaceslidable on the inner `surface of said` slip arms, said annular member formed to provide au inwardly extending shoulder about its inner periphery engageable with said neck head and an overshot tool-engageable head mounted slidably on said rst piston cylinder, a second piston rod connected to said motor piston and having a free end extending downwardly below saidmotor cylinder, means carried by said free end of said second piston rod for engagement with a body to be pulled, and means attachable to the upper end of said first piston rod for vertical movement of said piston rod.

2. In a hydraulic' pulling tool, a housing comprising a slip setting section provided with a plurality of interconnected slip members, apump section and a pulling section; said pump section comprising a pump cylin` der having a pump plunger slidably mounted therein and dividing said pump cylinder into an inlet end and an outer end; said pulling section comprising a plurality of motor cylinders each having a power piston slidably mounted therein and dividing each of said motor cylinders into a high pressure end and into a low pressure end, rst passage means liuidly communicating said pump cylinder outlet end with each of said motor cylinder high pressure ends, second passage means uidly communicating said pump cylinder inlet end and the low pressure end of the uppermost motor cylinder, third fluid passage means lluidly communicating the low pressure ends of each of said motor cylinders, a rst piston rod connected to said pump plunger and having a free end extending sealingly through the outlet end of said pump cylinder, biasing means arranged on said piston rod to bias said plunger toward the inlet end of said pump cylinder; said slip setting section comprising a cylindrical neck connected to said housing and having slidably mounted therein said first piston rod and having a longitudinally extending `slot in its lower end and a head at its upper end, slip arms slidably mounted on said neck, a frangible pin member vertically movable in said slot connecting said slip arms and said rst piston rod, an annular member slidably mounted for limited vertical movement on said neck member and having an outer tapered surface slidable on the inner surface of said slip arms, said annular member formed to provide an inwardly extending shoulder about its inner periphery engageable with said neck head and an overshot tool engageable head mounted slidably on said first piston rod, a second piston rod connected to each of said motor pistons and having a free end extending downwardly below the lowermost motor -cylinders, means carried by said free end of said piston rod for engagement with a body to be pulled, and means attachable to the upper end of said first piston rod for vertical movement of said first piston rod.

3. A hydraulic pulling tool comprising in combination an elongated casing having an upper pump cylinder provided with an inlet and an outlet adjacent its lower end and its upper end, respectively, and a lower motor cylinder having a lower pressure end and a high pressure end, said casing formed to provide fluid communication between the outlet of said pump cylinder and the high pressure end of said motor cylinder and also iiuid communication between the inlet of said pump cylinder and the low pressure end of said motor cylinder, a pump plunger connected to a first piston rod slidably arranged in said pump cylinder, said first piston rod having one end extending through the upper end of said pump cylinder and said elongated casing, means attachable to said one end of said first piston rod for applying upward force thereto, means to `bias said plunger and said first piston rod toward the lower end of said pump cylinder, a power piston connected to a second piston rod slidably arranged in said motor cylinder, one end of said second piston rod extending through the lower end of said motor cylinder and said elongated casing,V means carried by said end of said second piston rod for engaging with a body to be pulled, expansible interconnected slip members arranged on said elongated casing, a slip expander member also slidably arranged on said casing and engaging said slip members, said slip expander expanding said slip members upon relative vertical movement therebetween, frangible means connecting said slip members to said first piston rod, means on said casing for limiting upward vertical movement `of said slip members with said iirst piston rod, whereby when said device is engaged with the object to be pulled the first movement upward ofy said first piston rod causes expansion of said slip members and further upward movement breaks said frangible connection, affording free movement between saidfirst piston rod and said slip members.

4. A device in accordance with claim 3 in which a means 'for equalizing iluid pressure within `anclwithout said device is provided consisting of a flexible walledcomV tainer mounted in the low pressure end of the motor cylinder with its interior in fluid communication with the exterior of the elongated casing.

5 A hydraulic pulling tool comprising an upper-` 1pump assembly consisting of a pump cylinder with` a ,Y pump plunger arranged therein dividing said pump cylinderfinto an inlet end and an outlet end, a lirst pistonrod,connected to said plunger having one end extending, out the upper end of said pump cylinder, a lower motor assembly connected to said pump cylinder and consistingof apluraiity of vertically aligned motor cylinders, a motor piston in each of said motor cylinders dividing each of said` motor cylinders into a low pressure end anda high prest sure end, a second piston rod interconnecting each of said motor pistons having one end extending through the lowes end oi the lowerrnost motor cylinder and provided ,with

means on said end for engaging an obiect torbe pulled, means in the walls of said pump cylinderl and saidmotor cylinders providing duid communication betweentheoutlet end of said pump cylinder and the high pressure end of each motor cylinder and also means for providingfluid communication between the low pressure end of said motor cylinders and the inlet end of said pump cylinder, means arranged in said pump cylinder for biasing said plunger toward the inner end of said pump cylinder, a plurality of interconnected slip members slidably f arranged on said pump cylinder, a slip expander member also slidably arranged on said pump` cylinder for limited vertical movement thereon and engaging saidk slip members, frangible means connecting said slip members and said first piston rod, means provided on said pump cylinder to limit the vertical movement of said slip members with said first piston rod, whereby when the-device is engaged withthe object to be pulled, upward movement, of

sure end and a low pressure end, said housing formed to:`

provide first passage means fluidly connecting the outletY end of said. pump cylinder with each of the high pressurev ends of said motor cylinders, a second passage means uidly connecting the low pressure end of theuppermost of said motor cylinders with the inlet end of said pump- 4 cylinder, and a third passage means iluidly connecting the low pressure ends of each of said motor cylinders, a pres sure equalizer means mounted in the low pressure end of the uppermost motor cylinder including a llexible walled container and means lluidly connecting ,theinterior of said container with the exterior of said housing, a pump plunger slidably arranged in said pump` cylinder, a plunger rod connected to said pump plunger. with its free end extending upwardly through,v the upper end of said pump cylinder, a biasing means arranged to bias said plunger toward the inlet end of said pump cylindera power piston slidably mounted in each of said motork cylinders, each of said power pistons connected to a com-A mon pistonrod, said piston rod having its free end exf tending downwardly below the lowermost of said motor cylinders and said housing,vmeans carried on the lower end of said piston `rod for engaging with an objectto be pulled, means attached to the upper end of said piunger rod for applying vertical movement thereto, interconnected slip members slidably arranged about the upperend of said housing, a slip expander member slidably arranged for a limited vertical movement on the upper end of said housing and engaging said slip members,

frangible means connecting said slip members and said plunger rod whereby when said plunger rod is moved v upwardly, iirst the slip members are expanded by said expander member and `secondly the frangible connection is broken therefore affording free vertical movement of said plunger rod.

Smith et al Apr. 2,9, 1952 i 

